This invention is generally directed to imaging members, and more specifically, the present invention is directed to multi-layered photoconductive imaging members with a photogenerating layer, a charge transport layer, an optional hole blocking, or undercoat layer (UCL) and a top overcoat layer comprised of a crosslinked siloxane composite containing a caprolactone-siloxane copolymer group of Formula I
wherein R1 and R2 are each a substituent group selected from the group consisting of an alkyl having from 1 to about 6 carbons, a vinyl, and a phenyl; R″ represents a divalent linkage organic group, m and n represent the number of repeating segments, wherein m is from about 1 to about 100 and n is from about 1 to about 100, more specifically m is from about 10 to about 50 and n is from about 10 to about 50. More specifically, the present invention relates to photoconductive imaging members comprised of a supporting substrate, a hole blocking layer, an adhesive layer, a photogenerating layer, a charge, especially hole transport layer, and thereover a protective overcoating comprised of a crosslinked siloxane composite containing a caprolactone-siloxane copolymer group of Formula I and wherein there is enabled excellent electrical characteristics, minimization or the avoidance of humidity insensitivity, excellent image quality with substantially no background areas, low surface energy, and when the copolymer also contained in the charge transport layer improved adhesion between the charge transport layer and the overcoating layer. Moreover, in embodiments the overcoating layer illustrated herein can contain metal like alumina, such as alumina nanoparticles, and which particles can improve the durability and the mechanical characteristics of the overcoating layer.
In embodiments the photogenerating layer can be situated between the charge transport layer and the supporting substrate, and the hole blocking layer in contact with the supporting substrate can be situated between the supporting substrate and the photogenerating layer, which is comprised, for example, of the photogenerating pigments of U.S. Pat. No. 5,482,811, the disclosure of which is totally incorporated herein by reference, especially Type V hydroxygallium phthalocyanine, and generally metal free phthalocyanines, metal phthalocyanines, hydroxy gallium phthalocyanines, perylenes, titanyl phthalocyanines, selenium, selenium alloys, azo pigments, squaraines, and the like. The imaging members of the present invention in embodiments exhibit excellent cyclic/environmental stability; excellent wear characteristics; extended lifetimes of, for example, up to 3,000,000 imaging cycles; minimum microcracking; elimination/minimization of adverse affect when contacted with a number of solvents such as methylene chloride, tetrahydrofuran and toluene; acceptable and in some instances improved electrical characteristics; excellent imaging member surface properties; and which members can be selected for both drum and belt photoreceptors.
Processes of imaging, especially xerographic imaging, and printing, including digital, are also encompassed by the present invention. More specifically, the photoconductive imaging members of the present invention can be selected for a number of different known imaging and printing processes including, for example, electrophotographic imaging processes, especially xerographic imaging and printing processes wherein charged latent images are rendered visible with toner compositions of an appropriate charge polarity. The imaging members are in embodiments sensitive in the wavelength region of, for example, from about 475 to about 950 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the imaging members of this invention are useful in color xerographic applications, particularly high-speed color copying and printing processes.